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s390/kernel: fix ptrace peek/poke for floating point registers

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git commit 155e839a81
"s390/kernel: dynamically allocate FP register save area"
introduced a regression in regard to ptrace.

If the vector register extension is not present or unused the
ptrace peek of a floating pointer register return incorrect data
and the ptrace poke to a floating pointer register overwrites the
task structure starting at task->thread.fpu.fprs.

Cc: stable@kernel.org # v4.3
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky 2015-10-27 13:13:38 +01:00
parent ef12cb904e
commit 55a423b6f1
1 changed files with 4 additions and 4 deletions
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8
arch/s390/kernel/ptrace.c
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@ -244,7 +244,7 @@ static unsigned long __peek_user(struct task_struct *child, addr_t addr)
((addr_t) child->thread.fpu.vxrs + 2*offset);
else
tmp = *(addr_t *)
((addr_t) &child->thread.fpu.fprs + offset);
((addr_t) child->thread.fpu.fprs + offset);
} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
/*
@ -388,7 +388,7 @@ static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
child->thread.fpu.vxrs + 2*offset) = data;
else
*(addr_t *)((addr_t)
&child->thread.fpu.fprs + offset) = data;
child->thread.fpu.fprs + offset) = data;
} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
/*
@ -622,7 +622,7 @@ static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
((addr_t) child->thread.fpu.vxrs + 2*offset);
else
tmp = *(__u32 *)
((addr_t) &child->thread.fpu.fprs + offset);
((addr_t) child->thread.fpu.fprs + offset);
} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
/*
@ -747,7 +747,7 @@ static int __poke_user_compat(struct task_struct *child,
child->thread.fpu.vxrs + 2*offset) = tmp;
else
*(__u32 *)((addr_t)
&child->thread.fpu.fprs + offset) = tmp;
child->thread.fpu.fprs + offset) = tmp;
} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
/*